Refrigerating apparatus and method



March 18,1941. P. A. BANCEL Erm. 2,235,696,

` REFRIGERATINGAPHRATUS AND METHOD "Original Filed March 23, 1934 I THEIR ATT'oRNr-:Y

Patented Mar. 1s, 1941 PATENT oFFlcE RI'JIFRI(iERA'IlTN(lr APPARATUS AND METHOD Paul A. Bancei, Montclair, N. J., and John Kirgan,

Easton, Pa., assignors pany, Jersey City, N. Jersey to Ingersoll-Rand Com- J., a corporationof New Gontinuation of application Serial No. 716,938,

March. 23, 1934. This application iiled Novembei' 25, 1938. Serial N0. 242,230

16 Claims.

This invention is a continuation of our application Serial No. '716,938 led March 23, 1934, and relates to improvements in refrigerating apparatus, and especially to refrigerating apparatus 5- and a method of refrigeration in which the vaporlzatlo-n of a portion of a liquid refrigerant reduces the temperature of said refrigerant to the extent required.

An 'object of our invention is to provide refrigerating apparatus of the kind mentioned,

with an evaporator including a plurality of compartments or chambers, each equipped with an evacuator to carry away the vaporized portion.`

of the refrigerating medium, and suitable connections for controlling said apparatus, and en-` abling it to be adjusted to meet the requirements of a heavier or a lighter load, in a practical, eilicient and economical manner.

With refrigeratng systems using a non-volatile substance such as water as the refrigerating or Icooling medium, an evaporator in the form of a container for .water to'be chilled is employed.' The pressure in this evaporator is lowered to such a point that whenl water is admitted therey to at a given temperature, some of the water is immediately vaporized. Thus a body or mass of vwater Ain the evaporator 4can be cooled to the necessary .degree and utilized as needed. But the water vapor obtained from vaporization of part of the water must be removed from the evaporator, and this removal may be effected by a steam ejector. which carries the vapor to a condenser wherein the discharge o1' the ejector Vis liqueed. Such a system with a single evaporator chamber and a single ejector will serve quite well at approximately xed or predeter- ,mined loads. but it is quite unsuitable for operation when the load varies. Therefore, if such a system is built for a rated load it cannot be operated advantageously to give a reduced output, and if it is constructed for a small load the output cannot greatly be increased. .The cause of this is thelfact that the capacity oi the steam ejector or steam jet booster, that is, the pounds of Water vapor evacuated thereby in a given time at fixed suction 'pressure determined by the pressur@ in the evaporator itself, is substantially l constanaregardless of the amount of steam being used, Furthermore. the steam ejector is substantially a constant volume compressor and Vbecause of the peculiarcharacteristics of water vapor which cause the spccic volume to `increase as the vapor pressure and density decrease,'at reduced loads when 'the evaporator (Cl. (i2-152) temperature and Y vapor pressure therein have decreased the volume of vapor formed in a given v time is substantially the saine and the same rate of steam ow to the 'ejector is still required. -Yet another characteristic of the steam jet booster is that its steam flow must` be maintained at the rated value so long as the relation between the suction pressure (or chilled water temperature) in the evaporator and the discharge or condenser pressure remains constant. Hence this type of steam jet may become less 'and less economical to operate as the load thereon falls, and it must be turned on completely, using its full rated steam consumption, or completely off and rendered inoperative, so long 'as the aforemenl Vis equipped with several evaporator chambers v clude a plurality of chambers for evaporating and cooling water and an evacuator, such as a steam ejector, for each chamber, and means for allowing selective operation of one or more of said chambers. A further object thereof is to provide refrigerating apparatus having multiple evaporator chambers and means which can be readily actuated to put all or less than all of the chambers at Work as conditions demand.

Another object is to provide refrigerating apparatus which includes an evaporator having several chambers, each with its own evacuating means arranged so that the vaporized portion of the refrigerant can be delivered to an ordinary condenser. Thus we avoid a condenser of special and costly design, such as a' condenser having several chambers, with separate connections for same.

All the objects and advantages of the invention are `indicated in the following description? In the drawing Figure 1 shows refrigerating apparatus. partly in section, according to the invention,

Figure 2 is a section on line 2-2 of Figure 1; and

Figure 3 is a section on line 3 3 of Figure 1.

The numeral I is employed to indicate a water evaporator of any desired size or shape which contains a number of sections or compartments. three for example, indicated at 2, l and 4, formed between inside partitions 5 and the ends A water supply pipe or conduit is indicated.

at l, with branches 8 leading tol each of the aforesaid chambers or compartments. The branches terminate within said chambers in nozzles or sprayers 9, each of suillcient capacity. The pressure within any chamber of the evap rator I that is working will, of course, be low enough so that when water is admitted some of it will be vaporized at once and the remainder cooled to the required extent. If the temperature of the incoming water is 50 F., for instance, the system can be so designed and the pressure in the evaporator so reduced that the vaporizationV of a small part of the water admitted will cause the entire mass oi incoming water, when all three chambers are 1in operation, for example, to be cooled down to 47 F. In the branch pipes 8 are admission and cut-oil valves I0 so that one or more of the nozzles can be shut 0H whenever desired.

To carry oil the water thus chilled, we provide a common delivery means or conduit II connected by branches I2 with valves I3 therein to the separate compartmentsof the evaporator I. 'To these branches the chambers discharge through outlets in the bottom.

For removal of -the water vapor created by vapoirization in the chambers of the evaporator, steam ejectors or evacuators I4, in the form of L-shaped tubular members which communicate at one end with the inside of the chambers of the evaporator through openings I in the top. and are connected at their posite ends to a common discharge conduit I 6 which leads to a suitable condenser, are used. The ejectors receive steam nozzles I1 which are connected by pipes I8 to a common steam supply line I9, and

these branch pipes II each carry an admissionand shut-off valve shown at 20. The ejectors vnot only remove the water vapor, but maintain the necessary vacuum to vaporize some of the water in any chamber that is in operation.

With this arrangement any number of chambers in the evaporator from one up to the tbtal can be put into operation, or conversely rendered inoperative, as may be necessary.

If all are to Work at once, the valves I0 are all opened to admit water to the three chambers of the evaporator, and all of the steameiectors I4 are employed to carry away the water vapor to the condenser (not shown) by opening the valves 20. These ejectors compress the water vapor to the pressure in the condenser. and therefore are sometimes called thermo-com- The chilled water is withdrawn through the delivery pipe II with all valves I3 open. To cut out one or more chambers, the valves I0, I3 and 20 thereof are shut.

The drawing illustrates the chamber 4 as being out of service. In this chamber the level of the water may be maintained the same as the water level in the other two chambers. Any water trapped in the chamber 4. of course, can not flow out through the branch I2. I'he trapping of water in an inactive chamber, such as 4, is not a necessity and the only reason that it is done occasionally is to reduce the quantity of water circulating in the system and thereby avoiding flooding -of the active chambers. The 5 pressure in this chamber 4 may be slightly higher, that is to say, the vacuum therein is less because lthe steam jet thereof is not active and the pressure inside this compartment is'therefore equal to the pressure in the condenser. Hence no 10 vaporization takes place in chamber 4 but in the other two chambers a part of the water is vaporized as soon as it enters and' the water is exhausted through conduit I6. 'I'he chilled water is carried away as before by the conduit I I. l5

With this construction the system can be operated under a Wide range of conditions of varying load without waste of steam or power. In this type of refrigerating apparatus the capacity of a given steam ejector, that is, the number of pounds of water vapor drawn by the ejector from 'any chamber through the member It and compressed at a ilxeclv suction pressure, which is the pressure in the chamber above the cooled water therein, is approximately constant, re- 5 gardless oi' the amount of steam used. "Hence the amount of refrigeration in each chamber,- or the quantity of heat remove from any chamber, is also, undier the same conditions, approximately constant regardless of the amount of' water which flows through each chamber. That is, if the mass of water passing through any chamber is large, the temperature reduction is less than it will be if the mass of water is small, because the quantity of water vapor evacuated 35 by the steam jet is the same and therefore the quantity of heat extracted from the water does .not appreciably vary. Reference is here made to a booster which is operated with steam at approximately constant pressure and not to a series of ejectors designed for dierent pressures and steam flows. Therefore, to save steam under varying load conditions the evaporator is made with several chambers to serve as multiple units and the necessary control is provided by suitable means, such as branch pipes and the valves I0,

I3 and 20. Automatic regulation, of course, may also be practiced.

Preferably the quantity of water flowing through the pipe 1 to the evaporator is varied 50 -according to the amount of refrigerating enect needed at the place to which the chilled water is conducted. If all the chambers 2, 3 and 4 are working and the maximum amount of water is supplied thereto by the pipe 1, the chilled water leaving the evaporator may be at 47 F. At the place of use it may be all warmed up once more to 50, in which casethe maximum amount is again supplied to the evaporator I and all three chambers are used| to cool it again to 47. If, however, less refrigeration 'is needed the water may be so regulated that only two-thirds of the maximum runs through the pipe 1 to the evaporator. In that event only two of the chambers need be used, and, as the amount of vapor removed is the same as previously in each of these, the reduced quantity of water will be chilled to 47 as before. Further, if the load is again decreased the water can be regulated vas before so that only one-third of the maximum quantity runs through the pipe 1, and two ci the chambers will now be put out of operation. In this In stance the chamber which is working will cool the smaller volume of water which through it to such an extent that it is again 75 2.235.690 supplied through the delivery conduit Il at a which is neither increased nor decreased as it v ows from the header II to the place ofuse and back to the supply line 1. 4Assume the water is chilled i'rom 50 to 47V in .the evaporator I vwith all chambers working. 'Ihe water may again re-absorb enough heat at theplace to which it is conducted by the conduit Il, and where the refrigerating effect is desired, to raise its temperature to 50. When the water is returned to the evaporator I. i-t must of course be cooled by passing it through all three of the compartments 2, 3 and 4. If, however. Vthe same quantity is warmed only 2 so that the return temperature is 49, then two of the chambers are suflicient the pipes 8 and valves l0 are made large enough to transmit all of .the water supplied through the conduit 1, but the amount of water vapor which can be removed from each chamber by ,the ejecf tor thereof is always the same, regardless of the amount of water admittedthereto.

The branches I2 must also belarge enough so that each can carry oi from any chamber the maximum of the water supplied bythe conduit l.

In connection with the above described modes of operation, it should'be remembered that each steam ejector will extract water vapor from each chamber at a constant rate, and therefore remove heat from the Water itself at a constant rate only so long as the other factors heretofore mentioned are controlled in `the described manner to produce an absolute pressure in .the chambers which does not vary. This pressure must be relatively low in order to enable part of the incoming watervto be vaporized upon entrance. It the temperature of the inowing water drops below its normal full load value, the vaporization will be decreased, enabling .the electors to reduce the absolute pressure in each chamber above the level of the chilled water therein. This lower absolute pressure will result in a lowenchilled water tem perature. Such a drop in absolute pressure in the chambers 2, Brand l may take place, for lnstance, .ii the water is supplied through the pipe 'l thereto at a temperature lower than before, as when the apparatus is running at a given capacity, and the load is decreased without altering or reducing the number of chambers in operation. In that case the pressure in the chambers I will drop as above stated, and the chilled water willlbe cooled to a @temperature lower than desired. But this drop in pressure can be avoided by cutting out one or more chambers. and thereby maintaining the absolute pressure substantially constant in 'the remaining chambers.

In practice :the apparatus must always be operated with the controlling valves, especially the valves l0, in fully open or fully closed position,

so that each chamber is either in :lull operation,

. or completely cut out.

From 'the foregoing description it will be seen that operation oi the evaporator chambers can be selectively controlled by the means consisting of the water supply .pipe 'l` and delivery pipe II,

lwith the branch connections with the valves therein leading to the various chambers, and the branched steam supply lines with the valves therein, and no more steam is consumed than is necessitated by the load at any particular time.

Another important advantage is that, with the evaporator divided into separate chambers, all of .the steam electors can be arranged to deliver into the single discharge means or conduit I6 by which the water vapor and steam is conveyed to the condenser, and this condenser can be a condenser with a single chamber, because the multiple chambers on the interior of the evaporator I and .the use of the branched inlet and discharge conduits make a condenser with a number of chambers unnecessary. Likewise there is no necessity for cut-out valves' in the various evacuator casings Il. Of course. the conduit I6 may be omitted, and the ejectors can then be connectedto the condenser directly.

We cl-aim:

l. Refrlgerating apparatus having multiple chambers wherein a 4refrigerant is cooledvacuator members for saidchambers, refrigerant supply and delivery members for said chambers, the supply members being united and the delivery members being united. and means for selectively controlling the said members for rendering any chamber inactive at any instant and thereby selectively controlling the operation of said chambers.

2. Refrigerating apparatus having chambers for receiving a liquid refrigerant, a portion of which is to be vaporlzed therein, means common' to all of the chambers for supplying liquid refrigerant thereto, means common to all of the Ychambers for discharging liquid refrigerant chambers wherein a refrigerant is cooled, a common supply pipe for refrigerant having branches connected tn each of said chambers, common delivery means for refrigerant having branches `connected to each of said chambers, means to selectively control the flow of refrigerant through the branches connected to the chambers and stop :the ilow of refrigerant through any branch at any instant, and a selectively operable evacuator for each chamber for removing vapor from active chambers to selectively control the operation of the chambers' and render any 'chamber inactive at any instant, said evacuators being connected to maintain a substantially equal vac- -uum in all of the active chambers.

4. Refrigeratlng apparatus comprising chambers wherein a liquid refrigerant is cooled, means for selectively controlling the operation of said chambers -and for rendering any chamber inactive at-any instant including a supply pipe for refrigerant connected to each chamber, a delivery pipe for refrigerant having branches independently connected to each chamber, each branch ybeing of substantially the same capacity as the said delivery pipe, and selectively operable evacuators connected one to each chamber to remove vaporized refrigerant from 'the active chambers, the evacuators being connected to maintain a substantially equalvacuum in all of the active chambers.

5. The method of producing and controlling refrigeration consisting in admitting refrigerant to a plurality of chambers, extracting heat from the refrigerant in each of said chambers at a given pressure therein, and varying the number of chambers in operation to maintain the pressure and the quantity of. heat thus extracted substantially constant in each active chamber by rendering any chamber inactive at any instant.

6. The method of producing and controlling refrigeration which consists in admitting a liquid refrigerant to a plurality of chambers, extracting heat from the refrigerant by vaporizing a portion thereof in the chambers, maintaining substantially the same vaporization in all the chambers, and varying the number `of chambers in operation by rendering any chamber inactive at any instant to maintain said pressure and the quantity of heat extractedk in an active chamber substantially constant,

'7. 'I'he method of producing and controlling refrigeration consisting in dividing a liquid refrigerant into separate masses, vaporizing a portion of each mass to cool the remainder thereof, removing the vaporized portion, combining the cooled. masses for utilization, and varying the number of separate masses by stopping vaporization of any mass at any instant to regulate the amount of refrigeration capable of being effected by the combined' masses.

8. Refrigerating apparatus having a plurality of chambers for the evaporation of a refriger ant, independent 'evacuating means for each chamber, means common to all the chambers for admitting refrigerant to each chamber, means common to all the chambers for. delivering the of each of said masses, removing and compressing said portions,"selectively/stopping the vaporization of any one of said masses at any instant and subjecting it to the increased pressure of the vaporized portion of another of said masses.

10. Refrigerating apparatus having multiple chambers wherein a refrigerant is cooled, an evacuator member for each chamber, common refrigerant supply and delivery members for said chambers, and means to render inoperative the members associated with each one of said chambers thereby varying the combined capacity of the chambers by rendering any chamber inactive at any instant.

11. Refrigerating apparatus comprising a plurality of evaporator chambers wherein a liquid refrigerant is chilled by evaporation 'of a portion thereof, means common to all the chambers to distribute refrigerant thereto, means common to all the chambers to withdraw refrigerant therefrom, individual means to remove vaporized refrigerant from each chamber and ydischarge the same into a common condenser, and means associated with each one of the chambers to suspend refrigeration therein at any instant.

12. Refrigerating apparatus comprising a plurality of evaporator chambers wherein a liquid refrigerant is chilled by evaporation of a portion thereof, means common to all the chambers to distribute refrigerant thereto, means common to all the chambers to withdraw refrigerant from the chambers, individual means to remove vaporized refrigerant from each chamber, means to discharge the same into a common condenser, and means associated with each chamber to transfer its refrigerating load to the remainder of the chambers at any instant.

13. 'I'he method of cooling a liquid refrigerating medium which consists of dividing said medium into masses, removing heat from each mass by evaporating a part thereof, combining the treated masses for utilization thereof, and controlling the total refrigerating effect by varying theA number of masses into which the refrigerant is divided by stopping evaporation of any mass at any instant. 1

14. The, method of cooling a liquid refrigerating medium which consists of dividing said medium into masses, removing heat from each mass at a substantially uniform. rate by evaporating a .portion thereof, and varying the num-ber of masses into which the refrigerant is divided according to the total amount of cooling required by stopping evaporation of any mass at any instant.

15. In vapor jet apparatus for providing a supply of cooled liquid, ther combination of aplurality of evaporating chambers, an ejector connected to each chamber for withdrawing vapor therefrom to effect cooling of liquid therein by partial evaporation, and means for circulating -liquid selectively .through several evaporating chambers or through a smallernumber of said chambers and to render any chamber inactive at any instant to provide said supply of cooled liquid.

16. In a refrigerating apparatus, an evaporator having at least two chambers therein'to chill refrigerant, a refrigerant supply conduit for the evaporator, a supply valve for each chamber-to selectively Acontrol at any instant the iiow of refrigerant from the supply conduit to each chamber, a refrigerant discharge conduit for the evaporator, a discharge valve for each chamber to selectively control at any instant the iiow of refrigerant from each chamber to the supply conduit, a common steam header for the evaporator, a steam evacuator for each chamber to vaporize and chill the refrigerant, and a steam valve to control the flow of steam to each evaporator from theheader and thereby 'regulate the degree of refrigerant vaporization in the respective chambers, whereby any chamber may be selectively rendered inactive at any instant.

, PAUL A. BANCEL.

l JOHN KIRG'AN.y 

